Using implicit loop with -n
Topicalization and Special Variables example from a Well House Consultants training course
More on Topicalization and Special Variables [link]
Source code: spot Module: P210
=head1 Tiny code in Perl
The code above uses the -n option which implies
that it runs within a loop that reads each line
in turn from a file named on the command line
and stores it in the "default input and pattern
matching space" a.k.a. $_ ...
It's open to debate whether or not coding in this
way is good practise - my personal view is that
it's great for occasional utilities where you just
need to quickly filter a data file on one or two
occasions, but it's not a good idea for long term
coding where you need to have maintaiance in mind.
Dorothy:p82 grahamellis$ ./spot ../Downloads/access_log.xyz
o_whelk - - "GET /pub/graham/cliad.html HTTP/1.0" 200 323
sardine - - "GET /pub/graham/cliad.html HTTP/1.0" 200 323
mussel - - "GET /pub/graham/cliad.html HTTP/1.0" 200 323
skate - - "GET /pub/graham/cliad.html HTTP/1.0" 200 323
whale - - "GET /pub/graham/cliad.html HTTP/1.0" 200 323
trout - - "GET /pub/graham/cliad.html HTTP/1.0" 200 323
seal - - "GET /pub/graham/cliad.html HTTP/1.0" 200 323
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